A novel flavone-based fluorescent probe for relay recognition of HSO3- and Al3+

In this work, a new flavone-based fluorescent probe 3-hydroxy-3'-formylflavone (3HFF) was designed to achieve highly selective relay recognition of HSO3- and Al3+ in DMSO-H2O (2:8, v/v) solution. 3HFF displayed a highly selective response to HSO3- with a green fluorescence appearing at 524 nm. Moreover, the in situ generated 3HFF + HSO3- system demonstrated eminent relay recognition capability for Al3+ with a blue fluorescence appearing at 453 nm by the formation of a 1:1 complex between 3HFF and Al3+ in DMSO-H2O (2:8, v/v) solution. However, only slight change was observed in emission intensity with addition of Al3+ to 3HFF, and indicated HSO3- was essential for the sensing of Al3+. This work achieves the detection of HSO3- and Al3+ by only one probe and provides another example for this rare combination (anion/metal). (C) 2015 Elsevier B.V. All rights reserved.